Early Literacy Research Library (ELRL) - Article

Benefits of Pre-Kindergarten for Children in Baltimore, MD

Harden, B.J., et al. (2023) Benefits of Pre-Kindergarten for Children in Baltimore, MD. Early Childhood Research Quarterly, 64, 1-12.,

Access: Institutional Access

Publication year


study description

Regression Discontinuity

core topic(s)

Early Literacy

Population Characteristics

Poverty/Low-Income , Race, Ethnicity, and Culture , Toddler/Preschool , Urban

Exposures, Outcomes, Other

Disparity/Adversity , Implementation and Evaluation , Language and Literacy Development , Programs and Interventions (other) , School Readiness and Educational Outcomes


In this study, we use an RD approach to evaluate the effects of the Preschool Development Program in Baltimore, MD, a city with a large proportion of families from socioeconomically and racially marginalized backgrounds who contend with multiple environmental risks.


Pre-Kindergarten programs

outcomes evaluated

School readiness


Preschool programs in Baltimore, MD, a city with a large proportion of families from socioeconomically and racially marginalized backgrounds who contend with multiple environmental risks.


We compared a group of children who had received Pre-K (n = 554) to a group who had not yet participated in Pre-K (n = 542).

sample size

n=554 (children, Pre-K); n=542 (children, NO Pre-K)


  • Measure of Receptive Vocabulary: Peabody Picture Vocabulary Test-4 (PPVT)
  • Measure of Early Literacy: three subscales of the Woodcock-Johnson IV, 1) Letter-Word Identification, 2) Word Attack, 3) Passage Comprehension
  • Measure of Early Numeracy/Mathematics: Applied Problems subscale of the WJ
  • Measure of Executive Functioning: Head, Toes, Knees, and Shoulders (HTKS), a direct assessment of children’s behavioral self-regulation. This assessment includes components of executive functioning such as ability to focus attention, working memory, and inhibitory control.
  • Measure of Classroom Quality: Classroom Assessment Scoring System (CLASS) Preschool version, including 3 domains (and 10 dimensions/subscales): Emotional Support; Classroom Organization; and Instructional Support.


Results suggest that the Pre-K experience positively affects these children in a variety of domains, including language (d = 0.41–0.74), early literacy (d = 0.99–1.36), and early mathematical problem-solving (d = 0.54–0.71), a pattern of benefits which is consistent with the targets of the Pre-K curriculum in this jurisdiction. However, effects were not robust for executive functioning, a domain that has had less empirical attention in Pre-K evaluations. Importantly, our study also includes several enhancements to the Pre-K RD design that are recommended by experts but that have not been used widely in this literature.


Thus, this study contributes both to the literature on the benefits for children, from largely minoritized, low-income backgrounds, of preschool education implemented at scale and to the methodological literature on RD evaluations of Pre-K programs.


We discovered that the two cohorts differed at the cutoff point regarding two methodological issues (i.e., testing date, executive functioning assessment form type). We included these imbalanced variables as covariates in our analyses...In addition, although we had basic demographic and prior care data on both cohorts, we were unable to collect other data on family risk and protective factors that may have revealed whether Pre-K experiences were more or less beneficial for specific groups of children...Additionally, as explained, we found average group differences between the two cohorts on key outcome variables at baseline favoring the treatment group on average. One potential explanation for this finding is that the school district expanded the income eligibility range for Pre-K the year we collected baseline data from Cohort 2 (the comparison group). Although we only recruited children in the sample who were below 200% according to school personnel, it is possible that this policy change resulted in distinct Pre-K recruitment strategies overall for Cohort 2.